U.S. patent number 4,129,046 [Application Number 05/779,456] was granted by the patent office on 1978-12-12 for gear shift control.
This patent grant is currently assigned to Caterpillar Tractor Co.. Invention is credited to Howard R. Lemcke, Jr..
United States Patent |
4,129,046 |
Lemcke, Jr. |
December 12, 1978 |
Gear shift control
Abstract
An improved gear shift control for use in motor vehicle
transmissions of the type wherein gear shifter forks are slidably
mounted on associated elongated shifter rails within the housing of
the transmission. The gear shift control includes a selector gate
mounted within the transmission cover for rotation about a first
axis transverse to the longitudinal axis of the shifter rails. A
shift lever is mounted within the gate for rotation about a second
axis, generally perpendicular to and intersecting the first axis,
the lower end of the shift lever being selectively engageable with
the shifter forks for movement of the shifter forks on their
associated shifter rails. Tabs extend laterally from the lower end
of the selector gate to selectively engage at least one shifter
fork to prevent movement thereof during movement of another shifter
fork. Opposed springs are provided to center the selector gate in a
neutral position between changes in shifter fork positions.
Inventors: |
Lemcke, Jr.; Howard R. (Aurora,
IL) |
Assignee: |
Caterpillar Tractor Co.
(Peoria, IL)
|
Family
ID: |
25116509 |
Appl.
No.: |
05/779,456 |
Filed: |
March 21, 1977 |
Current U.S.
Class: |
74/473.33 |
Current CPC
Class: |
F16H
63/3408 (20130101); F16H 59/042 (20130101); F16H
63/20 (20130101); F16H 2059/0273 (20130101); F16H
2061/242 (20130101); Y10T 74/20159 (20150115) |
Current International
Class: |
F16H
63/34 (20060101); F16H 63/30 (20060101); F16H
59/04 (20060101); F16H 63/20 (20060101); F16H
63/08 (20060101); B60K 020/04 (); B60K
020/12 () |
Field of
Search: |
;74/473R,473P,477,470 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Culver; Horace M.
Attorney, Agent or Firm: Wegner, Stellman, McCord, Wiles
& Wood
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. A gear shift control for use in transmissions and the like
comprising:
a plurality of shifter rails;
a plurality of gear shifter forks each slidably mounted on an
associated shifter rail, each said shifter fork having a single
slot of uniform width;
a shift lever with a grippable end and an end selectively
engageable with each of said slots, said slots and said lever end
engageable therewith being of substantially identical dimension in
the longitudinal direction of said shifter rails;
means for mounting said shift lever for substantially universal
pivotal movement about a plurality of intersecting pivot axes;
a gear selector gate; and
means mounting said gate on said shift lever including means
connecting said gate to said lever for pivoting movement on a pivot
axis intersecting the pivot axes of said shift lever.
2. The gear shift control of claim 1 wherein the pivot axis of said
gate intersects one pivot axis of said shift lever at substantially
right angles.
3. The gear shift control of claim 1 wherein said means for
mounting said shift lever and said means for mounting said gate
include common parts.
4. A gear shift control for use in a transmission or the like
including a transmission housing, said housing including a pair of
opposed cavities therein facing the interior of said transmission
housing, said gear shift control comprising:
a plurality of longitudinally extending shifter rails within said
transmission housing;
a plurality of gear shifter forks each slidably mounted on an
associated shifter rail, each said fork having a single slot;
a gear selector gate, said gate having two opposed bosses
projecting therefrom and two opposed projections for abutment with
said housing;
a shift lever with a grippable actuating end and an operating end
selectively engageable with each of said slots and extending
through said selector gate;
a pair of pins mounted on said housing and pivotally mounting said
shifter gate for pivotal movement about a first axis;
means on said selector gate defining a pivot axis intersecting and
transverse to said first axis pivotally mounting said shift lever
intermediate its ends for pivotal movement relative to said
selector gate; and
two opposed springs, each said spring engaging one said boss and
being received in one said cavity in said housing to urge said gate
and said shift lever to a generally upright position.
Description
BACKGROUND OF THE INVENTION
This invention relates to gear shift controls used in motor vehicle
transmissions.
Typical motor vehicle transmissions include a plurality of
longitudinally extending shifter rails upon which shifter forks are
slidably mounted. Gears are individually associated with each fork
and move therewith.
A shift lever extends downwardly from the cover of the transmission
and terminates at a point slightly above the shifter rails so as to
allow the lower end of the shift lever to selectively engage one of
the shifter forks, as by capture of the lower end of the shift
lever between the exposed sides of an offset arm extending upwardly
from each of the shifter forks. Each of the shifter forks may be
selectively positioned at a predetermined point along its
associated shifter rail so as to place its associated gear in a
desired relation to other gears. Movement of the shift lever is
controlled by the operator of the vehicle.
When repositioning one of the shifter forks, it is desirable to
prevent movement of the other forks, as only one gear should be
engaged at one time. A gate is typically provided to prevent
unwanted movement. Such a gate may typically comprise a flat plate
mounted on gate rails for transverse movement in a plane above and
parallel to the plane of the shifter rails. The gate rails extend
in a direction perpendicular to that of the shifter rails. The
shift lever extends through a slot in the gate and effects movement
of the gate when moved in the direction perpendicular to the
direction of the shifter rails. Movement of the lever in a
direction parallel to the shifter rails does not cause movement of
the gate.
The gate is provided with downwardly extending tabs to engage at
least one shifter fork to prevent movement thereof when the shift
lever engages another fork which is to be repositioned. The shift
lever and gate may be returned to a neutral position when the gears
are disengaged. Springs are typically provided to urge the shift
lever and gate to a neutral position.
A problem associated with the above-described gear shifter is the
incorporation of multiple components in the combination shift
lever/selector gate, resulting in a higher cost and a less compact
arrangement than is desirable. Additionally, movement of the shift
lever in association with the slotted gate is a source of wear on
the components.
SUMMARY OF THE INVENTION
The present invention is directed to overcoming one or more of the
problems as set forth above.
According to the present invention, a compact gear shift control of
unitary construction is provided wherein the axis of rotation of
the shift lever intersects that of a rotatable selector gate.
Further, the shift lever is contained within the selector gate and
cooperates therewith to shift the shifter forks of a conventional
vehicle transmission. The combination selector gate shift lever is
centered within the transmission cover by opposed springs. Since
the shift lever and its associated gate pivot about intersecting
axes, a compact gear shifter which operates with a minimum amount
of friction is provided.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a transmission housing and
gear shift lever control embodying the features of the invention,
with some parts shown in dotted lines;
FIG. 2 is a vertical sectional view taken at right angles to the
view of FIG. 1;
FIG. 3 is an enlarged side elevational view of a portion of the
gear shift control, taken approximately along line 3--3 of FIG.
2;
FIG. 4 is a further enlarged side elevational view of a portion of
the gear shift control taken approximately along line 4--4 of FIG.
2; and
FIG. 5 is an elevational view of the gear shifter shown in FIG. 4
with the shift lever of the gear shifter in an alternate
position.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a gear shift control assembly 10 is provided
to shift the gears of a conventional vehicle transmission (not
shown) housed within a transmission housing 12 which includes a
transmission cover 14. A plurality of conventional shifter rails
extend longitudinally within the housing 12. For purposes of
illustration, three shifter rails 15, 16 and 17 (FIG. 2) are
provided. Three shifter forks 18, 19 and 20 are suspended, one from
each of the rails 15, 16 and 17, and are slidably mounted thereon
as by capture of each rail within a circular sleeve 21, the sleeves
21 being an integral part of each of the forks 18, 19 and 20. A
forked portion 22 of each shifter fork extends upwardly of each
sleeve 21. Selective positioning of each of the shifter forks 18,
19 and 20 on the rails 15, 16 and 17 serves to shift the gears of
the transmission in a pre-determined, conventional manner.
Shifting of the shifter forks is effected by means of the gear
shifter assembly 10, which is shown in FIG. 1 as including a shift
lever 24 which includes an upper, manually positionable section 26
and a lower section 28 extending downwardly from a pivot axis 30 at
the bottom of the section 26. The section 28 of the shift lever 24
includes a ball 34 at its lower extremity for selective engagement
with the forked portions 22 of the shifter forks. As seen in FIG.
1, the pivot axis 30 of the shift lever 24 lies in a plane 36 which
is at an angle to the horizontal. Such an angle allows the upper
section 26 of the shift lever 24 to be easily accessible to the
operator of the vehicle.
A selector gate 38 is suspended about a pivot axis 40 disposed in
the plane 36 and intersecting at right angles the pivot axis
30.
As seen in FIG. 1, the plane 36 of axes 30 and 40 parallels the
upper surface 42 of an upright support platform 44 situated on the
transmission cover 14. An arcuate cover 46 is provided on the
platform 44 and covers the pivot axes 30 and 40 of the shift lever
24 and the gate 38.
Referring now to FIG. 2, the components of the gear shift control
10 are shown in detail. The upper section 26 of the shift lever 24
enters the cover 46 through a generally conical opening 48 allowing
the section 26 to travel forwardly and toward the sides of the
opening 48. The pivot axis 30 is formed by two pins 50 extending
from the sides of the shift lever 26 into two bores 52 in the gate
38.
The lower section 28 of the shift lever 24 extends downwardly from
the pivot axis 30 between two tongues 54 of the gate 38. Each of
the tongues 54 extends downwardly from the pivot axis 30 to
approximately the level of the forked portions 22 of each of the
gear shifter forks 18, 19 and 20. Extending laterally outwardly
from the bottom of each tongue 54 are gate selector tabs 56, each
tab 56 being selectively positionable within the forked portion 22
of any of the gear selector forks 18, 19 or 20. Two stops 58 extend
oppositely and outwardly from each of the tongues 54 for abutment
against corners 60 and 62 within the transmission cover 14. Two
bosses 64 and 66 extend oppositely and outwardly from the tongues
54 from points above the stops 58, and retain the ends 67 of two
springs 68 and 70. The opposite ends 71 of the springs 68 and 70
are retained within cavities 72 and 74 located in the transmission
cover 14. The springs 68 and 70 are of approximately equal
compressive strength, and therefore serve to center the gate 38 at
approximately the position shown in FIG. 2 when no force is applied
to the upper section 26 of the shift lever 24.
Referring now to FIG. 3, the details of construction of the pivot
axis 40 and the interior of the support platform 44 are shown. The
pivot axis 40 is formed by two aligned pins 76 which extend from
the gate 38 to bores 78 within the support platform 44. The shift
lever 24 is free to rotate about the axis 30, while the gate 38 is
prevented from rotating in the same direction by the pins 76. Since
the pins 50 which form the axis 30 are contained within the gate
38, and the gate 38 is free to rotate laterally about the axis 40,
the shift lever 24 may rotate toward the left or right, as viewed
in FIG. 3, or in the direction perpendicular to the axis 40, or in
any direction between those extremes. However, the gate 38 is free
to rotate only about the axis 40.
Referring now to FIG. 4, the ball 34 of the shift lever portion 28
engages the forked portion 22 of the middle shifter fork 19 and the
gate selector tab 56 of the gate 38 engages the forked portion 22
of the shifter fork 20 shown to the right in FIG. 2. The
configuration shown in FIGS. 2 and 4 corresponds to a neutral gear
position. Referring to FIG. 5, the configuration of shifter forks
corresponding to a nonneutral gear position is illustrated. It may
be seen that the middle shifter fork 19 has been repositioned upon
the middle shifter rail 16, thereby shifting the gears of the
transmission in the conventional manner. As noted above, the gate
38 is not free to rotate so as to change its longitudinal position.
Therefore, even though the section 28 of the shift lever 24 may be
rotated longitudinally relative to the shifter rails, the gate 38
and, therefore, the gate tab 56 remain stationary relative to the
shifter rails. As a result, the shifter fork 20 appearing at the
right of FIG. 2 is retained in a stationary position on the right
hand shifter rail 17.
When it is desired to shift either shifter fork 18 or 20 the gate
38 and the shift lever 24 may be rotated about the axis 40 to place
the ball 34 in engagement with the forked portion 22 of the desired
shifter fork 18 or 20. The stops 58 prevent excessive rotation of
the gate 38, and automatically position the shift lever ball 34
within a forked portion 22. When the shift lever ball 34 is
positioned within the forked portion 22 of the shifter rail 18 or
20, one of the lateral gate tabs 56 is positioned within the forked
portion 22 of the remaining shifter rails so as to prevent shifting
thereof during the repositioning of either the left hand or
righthand shifter fork 18 or 20.
It will be appreciated that the present invention provides a more
compact gear shift control than possible previously by providing a
shift lever and an associated gate which pivot about intersecting
axes.
* * * * *